The present invention relates to electrical brazing, and particularly to a control circuit for preventing arcing at the brazing electrodes.
In performing a brazing operation, should the brazing electrodes fail to make good electrical contact with the metallic parts to be joined, arcing will invariably result. Such arcing needlessly erodes away the brazing electrodes, requiring their frequent replacement. The other main drawback to arcing is that the metallic parts are eroded as well. Normally, this is not a significant concern. However, in numerous applications the arc induced spattering of particles from the brazed parts can cause a deleterious fouling of the surrounding environment. This is particularly true in the manufacture or repair of electrical equipment, particularly when current carrying parts are spliced together by brazing. The spattered metallic particles can and do become lodged in the equipment and represent an often serious degradation of the equipment's dielectric integrity. In high voltage electrical equipment, these spattered metallic particles are particularly hazardous and have been known to precipitate ultimate equipment failure.
It is, accordingly, an object of the present invention to provide a control circuit operating to interrupt the flow of brazing current automatically upon the detection of arcing at the brazing electrodes.
A further object is to provide an anti-arcing control circuit of the above-character which can be readily adapted to both stationary brazing equipment and hand held brazing tools.
An additional object is to provide an anti-arcing control circuit of the above-character which is fail-safe in operation.
Another object is to provide an anti-arcing control circuit which is efficient in design, reliable in operation and convenient to use.
Other objects of the invention will, in part, be obvious and, in part, appear hereinafter.